This study was performed to evaluate the effect of pretreating dentin cavity walls and floor by silver nanoparticles on the color change of resin composite restorations with aging. Class V cavities were prepared on the buccal surface of 60 sound premolars. The teeth were divided into 2 main groups according to dentin surface pretreatment where A1 (no surface pretreatment) and A2 (surface pretreatment with silver nanoparticles). Each group was divided into three subgroups (n = 10) according to cavity depth, B1 (1mm depth), B2 (2mm depth) and B3 (3mm depth), each subgroup will be tested after 24h, one month and three months aging period in artificial saliva. The cavities were restored with resin composite with or without treatment with silver nanoparticles. Color assessment was done by spectrophotometer (VITA Easy shade compact). Optical density was measured using stereomicroscope. Ultra- structural examination of specimen interface was done by using the Environmental Scanning Electron Microscope. EDAX was used for assessment of the amount of silver nanoparticles presents at tooth restoration interface and at the bulk of composite restoration.